xref: /kernel/linux/linux-5.10/net/mac80211/rate.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2002-2005, Instant802 Networks, Inc.
4 * Copyright 2005-2006, Devicescape Software, Inc.
5 * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
6 * Copyright 2017	Intel Deutschland GmbH
7 */
8
9#include <linux/kernel.h>
10#include <linux/rtnetlink.h>
11#include <linux/module.h>
12#include <linux/slab.h>
13#include "rate.h"
14#include "ieee80211_i.h"
15#include "debugfs.h"
16
17struct rate_control_alg {
18	struct list_head list;
19	const struct rate_control_ops *ops;
20};
21
22static LIST_HEAD(rate_ctrl_algs);
23static DEFINE_MUTEX(rate_ctrl_mutex);
24
25static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
26module_param(ieee80211_default_rc_algo, charp, 0644);
27MODULE_PARM_DESC(ieee80211_default_rc_algo,
28		 "Default rate control algorithm for mac80211 to use");
29
30void rate_control_rate_init(struct sta_info *sta)
31{
32	struct ieee80211_local *local = sta->sdata->local;
33	struct rate_control_ref *ref = sta->rate_ctrl;
34	struct ieee80211_sta *ista = &sta->sta;
35	void *priv_sta = sta->rate_ctrl_priv;
36	struct ieee80211_supported_band *sband;
37	struct ieee80211_chanctx_conf *chanctx_conf;
38
39	ieee80211_sta_set_rx_nss(sta);
40
41	if (!ref)
42		return;
43
44	rcu_read_lock();
45
46	chanctx_conf = rcu_dereference(sta->sdata->vif.chanctx_conf);
47	if (WARN_ON(!chanctx_conf)) {
48		rcu_read_unlock();
49		return;
50	}
51
52	sband = local->hw.wiphy->bands[chanctx_conf->def.chan->band];
53
54	/* TODO: check for minstrel_s1g ? */
55	if (sband->band == NL80211_BAND_S1GHZ) {
56		ieee80211_s1g_sta_rate_init(sta);
57		rcu_read_unlock();
58		return;
59	}
60
61	spin_lock_bh(&sta->rate_ctrl_lock);
62	ref->ops->rate_init(ref->priv, sband, &chanctx_conf->def, ista,
63			    priv_sta);
64	spin_unlock_bh(&sta->rate_ctrl_lock);
65	rcu_read_unlock();
66	set_sta_flag(sta, WLAN_STA_RATE_CONTROL);
67}
68
69void rate_control_tx_status(struct ieee80211_local *local,
70			    struct ieee80211_supported_band *sband,
71			    struct ieee80211_tx_status *st)
72{
73	struct rate_control_ref *ref = local->rate_ctrl;
74	struct sta_info *sta = container_of(st->sta, struct sta_info, sta);
75	void *priv_sta = sta->rate_ctrl_priv;
76
77	if (!ref || !test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
78		return;
79
80	spin_lock_bh(&sta->rate_ctrl_lock);
81	if (ref->ops->tx_status_ext)
82		ref->ops->tx_status_ext(ref->priv, sband, priv_sta, st);
83	else if (st->skb)
84		ref->ops->tx_status(ref->priv, sband, st->sta, priv_sta, st->skb);
85	else
86		WARN_ON_ONCE(1);
87
88	spin_unlock_bh(&sta->rate_ctrl_lock);
89}
90
91void rate_control_rate_update(struct ieee80211_local *local,
92				    struct ieee80211_supported_band *sband,
93				    struct sta_info *sta, u32 changed)
94{
95	struct rate_control_ref *ref = local->rate_ctrl;
96	struct ieee80211_sta *ista = &sta->sta;
97	void *priv_sta = sta->rate_ctrl_priv;
98	struct ieee80211_chanctx_conf *chanctx_conf;
99
100	if (ref && ref->ops->rate_update) {
101		rcu_read_lock();
102
103		chanctx_conf = rcu_dereference(sta->sdata->vif.chanctx_conf);
104		if (WARN_ON(!chanctx_conf)) {
105			rcu_read_unlock();
106			return;
107		}
108
109		spin_lock_bh(&sta->rate_ctrl_lock);
110		ref->ops->rate_update(ref->priv, sband, &chanctx_conf->def,
111				      ista, priv_sta, changed);
112		spin_unlock_bh(&sta->rate_ctrl_lock);
113		rcu_read_unlock();
114	}
115	drv_sta_rc_update(local, sta->sdata, &sta->sta, changed);
116}
117
118int ieee80211_rate_control_register(const struct rate_control_ops *ops)
119{
120	struct rate_control_alg *alg;
121
122	if (!ops->name)
123		return -EINVAL;
124
125	mutex_lock(&rate_ctrl_mutex);
126	list_for_each_entry(alg, &rate_ctrl_algs, list) {
127		if (!strcmp(alg->ops->name, ops->name)) {
128			/* don't register an algorithm twice */
129			WARN_ON(1);
130			mutex_unlock(&rate_ctrl_mutex);
131			return -EALREADY;
132		}
133	}
134
135	alg = kzalloc(sizeof(*alg), GFP_KERNEL);
136	if (alg == NULL) {
137		mutex_unlock(&rate_ctrl_mutex);
138		return -ENOMEM;
139	}
140	alg->ops = ops;
141
142	list_add_tail(&alg->list, &rate_ctrl_algs);
143	mutex_unlock(&rate_ctrl_mutex);
144
145	return 0;
146}
147EXPORT_SYMBOL(ieee80211_rate_control_register);
148
149void ieee80211_rate_control_unregister(const struct rate_control_ops *ops)
150{
151	struct rate_control_alg *alg;
152
153	mutex_lock(&rate_ctrl_mutex);
154	list_for_each_entry(alg, &rate_ctrl_algs, list) {
155		if (alg->ops == ops) {
156			list_del(&alg->list);
157			kfree(alg);
158			break;
159		}
160	}
161	mutex_unlock(&rate_ctrl_mutex);
162}
163EXPORT_SYMBOL(ieee80211_rate_control_unregister);
164
165static const struct rate_control_ops *
166ieee80211_try_rate_control_ops_get(const char *name)
167{
168	struct rate_control_alg *alg;
169	const struct rate_control_ops *ops = NULL;
170
171	if (!name)
172		return NULL;
173
174	mutex_lock(&rate_ctrl_mutex);
175	list_for_each_entry(alg, &rate_ctrl_algs, list) {
176		if (!strcmp(alg->ops->name, name)) {
177			ops = alg->ops;
178			break;
179		}
180	}
181	mutex_unlock(&rate_ctrl_mutex);
182	return ops;
183}
184
185/* Get the rate control algorithm. */
186static const struct rate_control_ops *
187ieee80211_rate_control_ops_get(const char *name)
188{
189	const struct rate_control_ops *ops;
190	const char *alg_name;
191
192	kernel_param_lock(THIS_MODULE);
193	if (!name)
194		alg_name = ieee80211_default_rc_algo;
195	else
196		alg_name = name;
197
198	ops = ieee80211_try_rate_control_ops_get(alg_name);
199	if (!ops && name)
200		/* try default if specific alg requested but not found */
201		ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
202
203	/* Note: check for > 0 is intentional to avoid clang warning */
204	if (!ops && (strlen(CONFIG_MAC80211_RC_DEFAULT) > 0))
205		/* try built-in one if specific alg requested but not found */
206		ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
207
208	kernel_param_unlock(THIS_MODULE);
209
210	return ops;
211}
212
213#ifdef CONFIG_MAC80211_DEBUGFS
214static ssize_t rcname_read(struct file *file, char __user *userbuf,
215			   size_t count, loff_t *ppos)
216{
217	struct rate_control_ref *ref = file->private_data;
218	int len = strlen(ref->ops->name);
219
220	return simple_read_from_buffer(userbuf, count, ppos,
221				       ref->ops->name, len);
222}
223
224const struct file_operations rcname_ops = {
225	.read = rcname_read,
226	.open = simple_open,
227	.llseek = default_llseek,
228};
229#endif
230
231static struct rate_control_ref *
232rate_control_alloc(const char *name, struct ieee80211_local *local)
233{
234	struct rate_control_ref *ref;
235
236	ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
237	if (!ref)
238		return NULL;
239	ref->ops = ieee80211_rate_control_ops_get(name);
240	if (!ref->ops)
241		goto free;
242
243	ref->priv = ref->ops->alloc(&local->hw);
244	if (!ref->priv)
245		goto free;
246	return ref;
247
248free:
249	kfree(ref);
250	return NULL;
251}
252
253static void rate_control_free(struct ieee80211_local *local,
254			      struct rate_control_ref *ctrl_ref)
255{
256	ctrl_ref->ops->free(ctrl_ref->priv);
257
258#ifdef CONFIG_MAC80211_DEBUGFS
259	debugfs_remove_recursive(local->debugfs.rcdir);
260	local->debugfs.rcdir = NULL;
261#endif
262
263	kfree(ctrl_ref);
264}
265
266void ieee80211_check_rate_mask(struct ieee80211_sub_if_data *sdata)
267{
268	struct ieee80211_local *local = sdata->local;
269	struct ieee80211_supported_band *sband;
270	u32 user_mask, basic_rates = sdata->vif.bss_conf.basic_rates;
271	enum nl80211_band band;
272
273	if (WARN_ON(!sdata->vif.bss_conf.chandef.chan))
274		return;
275
276	band = sdata->vif.bss_conf.chandef.chan->band;
277	if (band == NL80211_BAND_S1GHZ) {
278		/* TODO */
279		return;
280	}
281
282	if (WARN_ON_ONCE(!basic_rates))
283		return;
284
285	user_mask = sdata->rc_rateidx_mask[band];
286	sband = local->hw.wiphy->bands[band];
287
288	if (user_mask & basic_rates)
289		return;
290
291	sdata_dbg(sdata,
292		  "no overlap between basic rates (0x%x) and user mask (0x%x on band %d) - clearing the latter",
293		  basic_rates, user_mask, band);
294	sdata->rc_rateidx_mask[band] = (1 << sband->n_bitrates) - 1;
295}
296
297static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
298{
299	struct sk_buff *skb = txrc->skb;
300	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
301	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
302	__le16 fc;
303
304	fc = hdr->frame_control;
305
306	return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
307			       IEEE80211_TX_CTL_USE_MINRATE)) ||
308		!ieee80211_is_data(fc);
309}
310
311static void rc_send_low_basicrate(struct ieee80211_tx_rate *rate,
312				  u32 basic_rates,
313				  struct ieee80211_supported_band *sband)
314{
315	u8 i;
316
317	if (sband->band == NL80211_BAND_S1GHZ) {
318		/* TODO */
319		rate->flags |= IEEE80211_TX_RC_S1G_MCS;
320		rate->idx = 0;
321		return;
322	}
323
324	if (basic_rates == 0)
325		return; /* assume basic rates unknown and accept rate */
326	if (rate->idx < 0)
327		return;
328	if (basic_rates & (1 << rate->idx))
329		return; /* selected rate is a basic rate */
330
331	for (i = rate->idx + 1; i <= sband->n_bitrates; i++) {
332		if (basic_rates & (1 << i)) {
333			rate->idx = i;
334			return;
335		}
336	}
337
338	/* could not find a basic rate; use original selection */
339}
340
341static void __rate_control_send_low(struct ieee80211_hw *hw,
342				    struct ieee80211_supported_band *sband,
343				    struct ieee80211_sta *sta,
344				    struct ieee80211_tx_info *info,
345				    u32 rate_mask)
346{
347	int i;
348	u32 rate_flags =
349		ieee80211_chandef_rate_flags(&hw->conf.chandef);
350
351	if (sband->band == NL80211_BAND_S1GHZ) {
352		info->control.rates[0].flags |= IEEE80211_TX_RC_S1G_MCS;
353		info->control.rates[0].idx = 0;
354		return;
355	}
356
357	if ((sband->band == NL80211_BAND_2GHZ) &&
358	    (info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
359		rate_flags |= IEEE80211_RATE_ERP_G;
360
361	info->control.rates[0].idx = 0;
362	for (i = 0; i < sband->n_bitrates; i++) {
363		if (!(rate_mask & BIT(i)))
364			continue;
365
366		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
367			continue;
368
369		if (!rate_supported(sta, sband->band, i))
370			continue;
371
372		info->control.rates[0].idx = i;
373		break;
374	}
375	WARN_ONCE(i == sband->n_bitrates,
376		  "no supported rates for sta %pM (0x%x, band %d) in rate_mask 0x%x with flags 0x%x\n",
377		  sta ? sta->addr : NULL,
378		  sta ? sta->supp_rates[sband->band] : -1,
379		  sband->band,
380		  rate_mask, rate_flags);
381
382	info->control.rates[0].count =
383		(info->flags & IEEE80211_TX_CTL_NO_ACK) ?
384		1 : hw->max_rate_tries;
385
386	info->control.skip_table = 1;
387}
388
389
390static bool rate_control_send_low(struct ieee80211_sta *pubsta,
391				  struct ieee80211_tx_rate_control *txrc)
392{
393	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
394	struct ieee80211_supported_band *sband = txrc->sband;
395	struct sta_info *sta;
396	int mcast_rate;
397	bool use_basicrate = false;
398
399	if (!pubsta || rc_no_data_or_no_ack_use_min(txrc)) {
400		__rate_control_send_low(txrc->hw, sband, pubsta, info,
401					txrc->rate_idx_mask);
402
403		if (!pubsta && txrc->bss) {
404			mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
405			if (mcast_rate > 0) {
406				info->control.rates[0].idx = mcast_rate - 1;
407				return true;
408			}
409			use_basicrate = true;
410		} else if (pubsta) {
411			sta = container_of(pubsta, struct sta_info, sta);
412			if (ieee80211_vif_is_mesh(&sta->sdata->vif))
413				use_basicrate = true;
414		}
415
416		if (use_basicrate)
417			rc_send_low_basicrate(&info->control.rates[0],
418					      txrc->bss_conf->basic_rates,
419					      sband);
420
421		return true;
422	}
423	return false;
424}
425
426static bool rate_idx_match_legacy_mask(s8 *rate_idx, int n_bitrates, u32 mask)
427{
428	int j;
429
430	/* See whether the selected rate or anything below it is allowed. */
431	for (j = *rate_idx; j >= 0; j--) {
432		if (mask & (1 << j)) {
433			/* Okay, found a suitable rate. Use it. */
434			*rate_idx = j;
435			return true;
436		}
437	}
438
439	/* Try to find a higher rate that would be allowed */
440	for (j = *rate_idx + 1; j < n_bitrates; j++) {
441		if (mask & (1 << j)) {
442			/* Okay, found a suitable rate. Use it. */
443			*rate_idx = j;
444			return true;
445		}
446	}
447	return false;
448}
449
450static bool rate_idx_match_mcs_mask(s8 *rate_idx, u8 *mcs_mask)
451{
452	int i, j;
453	int ridx, rbit;
454
455	ridx = *rate_idx / 8;
456	rbit = *rate_idx % 8;
457
458	/* sanity check */
459	if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
460		return false;
461
462	/* See whether the selected rate or anything below it is allowed. */
463	for (i = ridx; i >= 0; i--) {
464		for (j = rbit; j >= 0; j--)
465			if (mcs_mask[i] & BIT(j)) {
466				*rate_idx = i * 8 + j;
467				return true;
468			}
469		rbit = 7;
470	}
471
472	/* Try to find a higher rate that would be allowed */
473	ridx = (*rate_idx + 1) / 8;
474	rbit = (*rate_idx + 1) % 8;
475
476	for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
477		for (j = rbit; j < 8; j++)
478			if (mcs_mask[i] & BIT(j)) {
479				*rate_idx = i * 8 + j;
480				return true;
481			}
482		rbit = 0;
483	}
484	return false;
485}
486
487static bool rate_idx_match_vht_mcs_mask(s8 *rate_idx, u16 *vht_mask)
488{
489	int i, j;
490	int ridx, rbit;
491
492	ridx = *rate_idx >> 4;
493	rbit = *rate_idx & 0xf;
494
495	if (ridx < 0 || ridx >= NL80211_VHT_NSS_MAX)
496		return false;
497
498	/* See whether the selected rate or anything below it is allowed. */
499	for (i = ridx; i >= 0; i--) {
500		for (j = rbit; j >= 0; j--) {
501			if (vht_mask[i] & BIT(j)) {
502				*rate_idx = (i << 4) | j;
503				return true;
504			}
505		}
506		rbit = 15;
507	}
508
509	/* Try to find a higher rate that would be allowed */
510	ridx = (*rate_idx + 1) >> 4;
511	rbit = (*rate_idx + 1) & 0xf;
512
513	for (i = ridx; i < NL80211_VHT_NSS_MAX; i++) {
514		for (j = rbit; j < 16; j++) {
515			if (vht_mask[i] & BIT(j)) {
516				*rate_idx = (i << 4) | j;
517				return true;
518			}
519		}
520		rbit = 0;
521	}
522	return false;
523}
524
525static void rate_idx_match_mask(s8 *rate_idx, u16 *rate_flags,
526				struct ieee80211_supported_band *sband,
527				enum nl80211_chan_width chan_width,
528				u32 mask,
529				u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
530				u16 vht_mask[NL80211_VHT_NSS_MAX])
531{
532	if (*rate_flags & IEEE80211_TX_RC_VHT_MCS) {
533		/* handle VHT rates */
534		if (rate_idx_match_vht_mcs_mask(rate_idx, vht_mask))
535			return;
536
537		*rate_idx = 0;
538		/* keep protection flags */
539		*rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
540				IEEE80211_TX_RC_USE_CTS_PROTECT |
541				IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
542
543		*rate_flags |= IEEE80211_TX_RC_MCS;
544		if (chan_width == NL80211_CHAN_WIDTH_40)
545			*rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
546
547		if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
548			return;
549
550		/* also try the legacy rates. */
551		*rate_flags &= ~(IEEE80211_TX_RC_MCS |
552				 IEEE80211_TX_RC_40_MHZ_WIDTH);
553		if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
554					       mask))
555			return;
556	} else if (*rate_flags & IEEE80211_TX_RC_MCS) {
557		/* handle HT rates */
558		if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
559			return;
560
561		/* also try the legacy rates. */
562		*rate_idx = 0;
563		/* keep protection flags */
564		*rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
565				IEEE80211_TX_RC_USE_CTS_PROTECT |
566				IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
567		if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
568					       mask))
569			return;
570	} else {
571		/* handle legacy rates */
572		if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
573					       mask))
574			return;
575
576		/* if HT BSS, and we handle a data frame, also try HT rates */
577		switch (chan_width) {
578		case NL80211_CHAN_WIDTH_20_NOHT:
579		case NL80211_CHAN_WIDTH_5:
580		case NL80211_CHAN_WIDTH_10:
581			return;
582		default:
583			break;
584		}
585
586		*rate_idx = 0;
587		/* keep protection flags */
588		*rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
589				IEEE80211_TX_RC_USE_CTS_PROTECT |
590				IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
591
592		*rate_flags |= IEEE80211_TX_RC_MCS;
593
594		if (chan_width == NL80211_CHAN_WIDTH_40)
595			*rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
596
597		if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
598			return;
599	}
600
601	/*
602	 * Uh.. No suitable rate exists. This should not really happen with
603	 * sane TX rate mask configurations. However, should someone manage to
604	 * configure supported rates and TX rate mask in incompatible way,
605	 * allow the frame to be transmitted with whatever the rate control
606	 * selected.
607	 */
608}
609
610static void rate_fixup_ratelist(struct ieee80211_vif *vif,
611				struct ieee80211_supported_band *sband,
612				struct ieee80211_tx_info *info,
613				struct ieee80211_tx_rate *rates,
614				int max_rates)
615{
616	struct ieee80211_rate *rate;
617	bool inval = false;
618	int i;
619
620	/*
621	 * Set up the RTS/CTS rate as the fastest basic rate
622	 * that is not faster than the data rate unless there
623	 * is no basic rate slower than the data rate, in which
624	 * case we pick the slowest basic rate
625	 *
626	 * XXX: Should this check all retry rates?
627	 */
628	if (!(rates[0].flags &
629	      (IEEE80211_TX_RC_MCS | IEEE80211_TX_RC_VHT_MCS))) {
630		u32 basic_rates = vif->bss_conf.basic_rates;
631		s8 baserate = basic_rates ? ffs(basic_rates) - 1 : 0;
632
633		rate = &sband->bitrates[rates[0].idx];
634
635		for (i = 0; i < sband->n_bitrates; i++) {
636			/* must be a basic rate */
637			if (!(basic_rates & BIT(i)))
638				continue;
639			/* must not be faster than the data rate */
640			if (sband->bitrates[i].bitrate > rate->bitrate)
641				continue;
642			/* maximum */
643			if (sband->bitrates[baserate].bitrate <
644			     sband->bitrates[i].bitrate)
645				baserate = i;
646		}
647
648		info->control.rts_cts_rate_idx = baserate;
649	}
650
651	for (i = 0; i < max_rates; i++) {
652		/*
653		 * make sure there's no valid rate following
654		 * an invalid one, just in case drivers don't
655		 * take the API seriously to stop at -1.
656		 */
657		if (inval) {
658			rates[i].idx = -1;
659			continue;
660		}
661		if (rates[i].idx < 0) {
662			inval = true;
663			continue;
664		}
665
666		/*
667		 * For now assume MCS is already set up correctly, this
668		 * needs to be fixed.
669		 */
670		if (rates[i].flags & IEEE80211_TX_RC_MCS) {
671			WARN_ON(rates[i].idx > 76);
672
673			if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
674			    info->control.use_cts_prot)
675				rates[i].flags |=
676					IEEE80211_TX_RC_USE_CTS_PROTECT;
677			continue;
678		}
679
680		if (rates[i].flags & IEEE80211_TX_RC_VHT_MCS) {
681			WARN_ON(ieee80211_rate_get_vht_mcs(&rates[i]) > 9);
682			continue;
683		}
684
685		/* set up RTS protection if desired */
686		if (info->control.use_rts) {
687			rates[i].flags |= IEEE80211_TX_RC_USE_RTS_CTS;
688			info->control.use_cts_prot = false;
689		}
690
691		/* RC is busted */
692		if (WARN_ON_ONCE(rates[i].idx >= sband->n_bitrates)) {
693			rates[i].idx = -1;
694			continue;
695		}
696
697		rate = &sband->bitrates[rates[i].idx];
698
699		/* set up short preamble */
700		if (info->control.short_preamble &&
701		    rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
702			rates[i].flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
703
704		/* set up G protection */
705		if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
706		    info->control.use_cts_prot &&
707		    rate->flags & IEEE80211_RATE_ERP_G)
708			rates[i].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT;
709	}
710}
711
712
713static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
714					struct ieee80211_tx_info *info,
715					struct ieee80211_tx_rate *rates,
716					int max_rates)
717{
718	struct ieee80211_sta_rates *ratetbl = NULL;
719	int i;
720
721	if (sta && !info->control.skip_table)
722		ratetbl = rcu_dereference(sta->rates);
723
724	/* Fill remaining rate slots with data from the sta rate table. */
725	max_rates = min_t(int, max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
726	for (i = 0; i < max_rates; i++) {
727		if (i < ARRAY_SIZE(info->control.rates) &&
728		    info->control.rates[i].idx >= 0 &&
729		    info->control.rates[i].count) {
730			if (rates != info->control.rates)
731				rates[i] = info->control.rates[i];
732		} else if (ratetbl) {
733			rates[i].idx = ratetbl->rate[i].idx;
734			rates[i].flags = ratetbl->rate[i].flags;
735			if (info->control.use_rts)
736				rates[i].count = ratetbl->rate[i].count_rts;
737			else if (info->control.use_cts_prot)
738				rates[i].count = ratetbl->rate[i].count_cts;
739			else
740				rates[i].count = ratetbl->rate[i].count;
741		} else {
742			rates[i].idx = -1;
743			rates[i].count = 0;
744		}
745
746		if (rates[i].idx < 0 || !rates[i].count)
747			break;
748	}
749}
750
751static bool rate_control_cap_mask(struct ieee80211_sub_if_data *sdata,
752				  struct ieee80211_supported_band *sband,
753				  struct ieee80211_sta *sta, u32 *mask,
754				  u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
755				  u16 vht_mask[NL80211_VHT_NSS_MAX])
756{
757	u32 i, flags;
758
759	*mask = sdata->rc_rateidx_mask[sband->band];
760	flags = ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chandef);
761	for (i = 0; i < sband->n_bitrates; i++) {
762		if ((flags & sband->bitrates[i].flags) != flags)
763			*mask &= ~BIT(i);
764	}
765
766	if (*mask == (1 << sband->n_bitrates) - 1 &&
767	    !sdata->rc_has_mcs_mask[sband->band] &&
768	    !sdata->rc_has_vht_mcs_mask[sband->band])
769		return false;
770
771	if (sdata->rc_has_mcs_mask[sband->band])
772		memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[sband->band],
773		       IEEE80211_HT_MCS_MASK_LEN);
774	else
775		memset(mcs_mask, 0xff, IEEE80211_HT_MCS_MASK_LEN);
776
777	if (sdata->rc_has_vht_mcs_mask[sband->band])
778		memcpy(vht_mask, sdata->rc_rateidx_vht_mcs_mask[sband->band],
779		       sizeof(u16) * NL80211_VHT_NSS_MAX);
780	else
781		memset(vht_mask, 0xff, sizeof(u16) * NL80211_VHT_NSS_MAX);
782
783	if (sta) {
784		__le16 sta_vht_cap;
785		u16 sta_vht_mask[NL80211_VHT_NSS_MAX];
786
787		/* Filter out rates that the STA does not support */
788		*mask &= sta->supp_rates[sband->band];
789		for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++)
790			mcs_mask[i] &= sta->ht_cap.mcs.rx_mask[i];
791
792		sta_vht_cap = sta->vht_cap.vht_mcs.rx_mcs_map;
793		ieee80211_get_vht_mask_from_cap(sta_vht_cap, sta_vht_mask);
794		for (i = 0; i < NL80211_VHT_NSS_MAX; i++)
795			vht_mask[i] &= sta_vht_mask[i];
796	}
797
798	return true;
799}
800
801static void
802rate_control_apply_mask_ratetbl(struct sta_info *sta,
803				struct ieee80211_supported_band *sband,
804				struct ieee80211_sta_rates *rates)
805{
806	int i;
807	u32 mask;
808	u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
809	u16 vht_mask[NL80211_VHT_NSS_MAX];
810	enum nl80211_chan_width chan_width;
811
812	if (!rate_control_cap_mask(sta->sdata, sband, &sta->sta, &mask,
813				   mcs_mask, vht_mask))
814		return;
815
816	chan_width = sta->sdata->vif.bss_conf.chandef.width;
817	for (i = 0; i < IEEE80211_TX_RATE_TABLE_SIZE; i++) {
818		if (rates->rate[i].idx < 0)
819			break;
820
821		rate_idx_match_mask(&rates->rate[i].idx, &rates->rate[i].flags,
822				    sband, chan_width, mask, mcs_mask,
823				    vht_mask);
824	}
825}
826
827static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
828				    struct ieee80211_sta *sta,
829				    struct ieee80211_supported_band *sband,
830				    struct ieee80211_tx_rate *rates,
831				    int max_rates)
832{
833	enum nl80211_chan_width chan_width;
834	u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
835	u32 mask;
836	u16 rate_flags, vht_mask[NL80211_VHT_NSS_MAX];
837	int i;
838
839	/*
840	 * Try to enforce the rateidx mask the user wanted. skip this if the
841	 * default mask (allow all rates) is used to save some processing for
842	 * the common case.
843	 */
844	if (!rate_control_cap_mask(sdata, sband, sta, &mask, mcs_mask,
845				   vht_mask))
846		return;
847
848	/*
849	 * Make sure the rate index selected for each TX rate is
850	 * included in the configured mask and change the rate indexes
851	 * if needed.
852	 */
853	chan_width = sdata->vif.bss_conf.chandef.width;
854	for (i = 0; i < max_rates; i++) {
855		/* Skip invalid rates */
856		if (rates[i].idx < 0)
857			break;
858
859		rate_flags = rates[i].flags;
860		rate_idx_match_mask(&rates[i].idx, &rate_flags, sband,
861				    chan_width, mask, mcs_mask, vht_mask);
862		rates[i].flags = rate_flags;
863	}
864}
865
866void ieee80211_get_tx_rates(struct ieee80211_vif *vif,
867			    struct ieee80211_sta *sta,
868			    struct sk_buff *skb,
869			    struct ieee80211_tx_rate *dest,
870			    int max_rates)
871{
872	struct ieee80211_sub_if_data *sdata;
873	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
874	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
875	struct ieee80211_supported_band *sband;
876
877	rate_control_fill_sta_table(sta, info, dest, max_rates);
878
879	if (!vif)
880		return;
881
882	sdata = vif_to_sdata(vif);
883	sband = sdata->local->hw.wiphy->bands[info->band];
884
885	if (ieee80211_is_data(hdr->frame_control))
886		rate_control_apply_mask(sdata, sta, sband, dest, max_rates);
887
888	if (dest[0].idx < 0)
889		__rate_control_send_low(&sdata->local->hw, sband, sta, info,
890					sdata->rc_rateidx_mask[info->band]);
891
892	if (sta)
893		rate_fixup_ratelist(vif, sband, info, dest, max_rates);
894}
895EXPORT_SYMBOL(ieee80211_get_tx_rates);
896
897void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
898			   struct sta_info *sta,
899			   struct ieee80211_tx_rate_control *txrc)
900{
901	struct rate_control_ref *ref = sdata->local->rate_ctrl;
902	void *priv_sta = NULL;
903	struct ieee80211_sta *ista = NULL;
904	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
905	int i;
906
907	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
908		info->control.rates[i].idx = -1;
909		info->control.rates[i].flags = 0;
910		info->control.rates[i].count = 0;
911	}
912
913	if (rate_control_send_low(sta ? &sta->sta : NULL, txrc))
914		return;
915
916	if (ieee80211_hw_check(&sdata->local->hw, HAS_RATE_CONTROL))
917		return;
918
919	if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
920		ista = &sta->sta;
921		priv_sta = sta->rate_ctrl_priv;
922	}
923
924	if (ista) {
925		spin_lock_bh(&sta->rate_ctrl_lock);
926		ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
927		spin_unlock_bh(&sta->rate_ctrl_lock);
928	} else {
929		rate_control_send_low(NULL, txrc);
930	}
931
932	if (ieee80211_hw_check(&sdata->local->hw, SUPPORTS_RC_TABLE))
933		return;
934
935	ieee80211_get_tx_rates(&sdata->vif, ista, txrc->skb,
936			       info->control.rates,
937			       ARRAY_SIZE(info->control.rates));
938}
939
940int rate_control_set_rates(struct ieee80211_hw *hw,
941			   struct ieee80211_sta *pubsta,
942			   struct ieee80211_sta_rates *rates)
943{
944	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
945	struct ieee80211_sta_rates *old;
946	struct ieee80211_supported_band *sband;
947
948	sband = ieee80211_get_sband(sta->sdata);
949	if (!sband)
950		return -EINVAL;
951	rate_control_apply_mask_ratetbl(sta, sband, rates);
952	/*
953	 * mac80211 guarantees that this function will not be called
954	 * concurrently, so the following RCU access is safe, even without
955	 * extra locking. This can not be checked easily, so we just set
956	 * the condition to true.
957	 */
958	old = rcu_dereference_protected(pubsta->rates, true);
959	rcu_assign_pointer(pubsta->rates, rates);
960	if (old)
961		kfree_rcu(old, rcu_head);
962
963	if (sta->uploaded)
964		drv_sta_rate_tbl_update(hw_to_local(hw), sta->sdata, pubsta);
965
966	ieee80211_sta_set_expected_throughput(pubsta, sta_get_expected_throughput(sta));
967
968	return 0;
969}
970EXPORT_SYMBOL(rate_control_set_rates);
971
972int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
973				 const char *name)
974{
975	struct rate_control_ref *ref;
976
977	ASSERT_RTNL();
978
979	if (local->open_count)
980		return -EBUSY;
981
982	if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL)) {
983		if (WARN_ON(!local->ops->set_rts_threshold))
984			return -EINVAL;
985		return 0;
986	}
987
988	ref = rate_control_alloc(name, local);
989	if (!ref) {
990		wiphy_warn(local->hw.wiphy,
991			   "Failed to select rate control algorithm\n");
992		return -ENOENT;
993	}
994
995	WARN_ON(local->rate_ctrl);
996	local->rate_ctrl = ref;
997
998	wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
999		    ref->ops->name);
1000
1001	return 0;
1002}
1003
1004void rate_control_deinitialize(struct ieee80211_local *local)
1005{
1006	struct rate_control_ref *ref;
1007
1008	ref = local->rate_ctrl;
1009
1010	if (!ref)
1011		return;
1012
1013	local->rate_ctrl = NULL;
1014	rate_control_free(local, ref);
1015}
1016